Couple of questions

[Bassbme]

I've been making some injection molds using Durham's Water Putty. I tried my first one out today, and other than a serious design flaw, the bait itself turned out pretty well. The design flaw is that I had the sprue ( I guess it's called) coming in on the side of the bait, and I used a trimmed down Yum dinger for the channel. I butted the dinger right up to the bait which made it way too big. Should have looked at a different Youtube video lol

Anyhow, I'm changing that part of the design and I'd like to ask how large of a gate or channel would you have going to the bait cavity itself? 3/16" diameter? Smaller? Larger?  It's only a 2 bait mold, if that makes any difference.

Also, as part of my newbie getting started orders, I had gotten one of the plastisol samplers from Bait Plastics. I really liked the firmness of their medium/saltwater, so what I would like to do is mix the bottle of medium that came with the sampler, with the bottle of saltwater that came with the sampler, to come up with what would be equivalent to their medium/saltwater. Would anyone know if I need to use a 50/50 mix, or is it just something I am going to have to experiment with?

Any help would be much appreciated. Also, can anyone clue me in to the terminology for the different parts of an injection mold? If so I would greatly appreciate it. Drives me nuts not knowing what to call something. Especially when I am asking questions about it. lol

Thanks again peoples

[Fishermanbt]

Not 100% on this but the part where the injector goes in is the spur.  The part where you top off after injecting. The channel leading to the baits is the runner. 

The size of the runner tends to be determined by the size of the bait. This is because as the bait cools it is drawing hot plastic from the runner. This keeps the bait from denting. For example my Jacobs 3” silver fish has a 5/16” runner. It is a thin profile bait. Where as I have a 3.5” grub mold that has a 5/8” runner. It has a thicker body.

As far as mixing plastics I don’t have a straight answer other than trial and error. 

[Bassbme]

Fishermanbt, thank you very much for responding. I definitely appreciate the vocabulary lesson. Knowing the names of what I am talking about is kind of a pet peeve of mine. So as I said, I appreciate the definitions you provided. I also didn't know about the bait cooling and drawing hot plastic from the runner. That's pretty cool!

The bottom half of my new molds are drying right now. They're both Frankenstein baits. A Craw/ tube bait. so none of the walls or parts of the bait are really all that thick. I used pieces of 1/8"  diameter plastic rod to mold the runners. One of the baits will be 3 1/2" and the other 4 1/2"  I haven't tried shooting them yet. Just hope the 1/8" diameter is good enough to get a good fill. Nice thing about making them out of Durham's is that it will be easy to open them up if need be.

And your reply concerning mixing the different firmness plastics is about what I expected. Do it and see what I come up with.

Again thank you for replying. I truly appreciate it.

[Bassbme]

Finally got around to sealing the new injection molds I made and shot the first baits from them. The design is much better, and aside from a little of that pesky flash, I think baits turned out pretty well.

They're actually 3 1/4" and 4" respectively.

[mark poulson]

Those look good!

 

[Bassbme]

Thanks Mark. Much appreciated !!!

I was down shooting some more baits and think I may have solved the little bit of flash problem I have. In reading past posts I had read that to avoid the dimpling that can happen with injected baits, that you need to hold pressure on the injector for a period of time before you remove it from the mold.

On my first shoots I wanted to make sure I got a good cavity fill so I used a lot of pressure and held it like that for a bit. I thought the amount of pressure I was bringing the mold to was probably causing the flash, so I decreased the pressure a bit. 3 of the 7 baits I shot had slight dimples in the side of the craws head. But I had almost zero flash.

I'm thinking maybe the same amount of pressure but holding it a little longer will eliminate the occasional dimple. The dimples aren't bad, but they're there.

And thanks again for the compliment. Truly appreciated

[jigmeister]

Nice work there !    You have actually made a 3 part mold including the rod for the tube part . 

20 years  or so a go  I made up a similar 3 part mold also using  Durhams for a Mad Man craw for the master  . I was having trouble getting the mold cavity to completely fill at the outer extremities such as the tips of the claws .

I began using a shop vac to create vacuum and experimented with hand scribed vent  lines in the mold halves to draw plastic where it was needed by using different   vacuum levels . 

I didn't have to pressurize the plastic simply pour it into the sprue and let the vacuum do the rest 

After I got it dialed in it worked pretty good . 

[Bassbme]

jigmeister, thanks for the response, and the compliment. Much appreciated. Those Mad Man craws were awesome baits. I still actually have 3 of the original Mad Man Craws left. I loved those baits,  This is pretty much a Mad Man craw front half, as I used the front part of a Yum Craw Bug for that part of the bait. From what I read way back then, Yum bought the molds from Mad Man, or something to that effect.

Anyhow, the entire reason I made these baits is to have a bait that would actually accept an actual tube jig.  As I am sure you know, the Mad Man's and the Yum Craw Bugs are just too short. I have two different length rods that I can use for shooting these baits. One that has a thin head so it will accept the length of a tube jig, and another that's shorter and will leave more meat in the head to accept a Trokar TK190 tube hook. I use Owner Wide Gap Plus hooks for a lot of my soft plastics, and the thicker head will probably accept the Owner hooks as well, but I determined the head thickness with the TK 190 in mind. I had been using baits that I Frankensteined together using Mend It. But these are much better and I can make them in any color combination that I want.

That's a slick idea you had with the vacuum system. And I know what you mean about the need to vent molds. I don't have a problem with these molds filling completely, but I do have a thick bodied ring worm type bait that I am currently playing with the mold. It has a small curly tail on it and I am having a little trouble getting the curly tail to fill completely. I built it with grooves at the tip of the tail, but I think I need to drill a hole at the end of grooves to let more air out. I'm going to go down and mess with it here shortly.  Once again, thank you for the response and compliment. Truly appreciated.

[Bassbme]

Oh and does this picture look familiar? It's one of the last 3 that I have.

[bryanmc]

On 5/19/2020 at 7:26 PM, Fishermanbt said:

Not 100% on this but the part where the injector goes in is the spur.  The part where you top off after injecting. The channel leading to the baits is the runner. 

*sprue*, not spur. 

 

Edited May 31, 2020 by bryanmc

[jigmeister]

5 hours ago, Bassbme said:

Oh and does this picture look familiar? It's one of the last 3 that I have.

Bassbme ,  I thought I had seen a couple of these baits I made left so I found them and took a picture . These are based on  the medium sized Mad Mans

The baits being dark (Junebug ) the details don't show up that good in the picture . I changed the legs because they were stiff on the original and just didn't look fluid and life like in the water . I also changed the antennae a little and used silicone skirt strands  because they float up and move around more naturally .  

[Bassbme]

Jigmeister,  those look really good. And you can definitely tell they're made using a Mad Man bait as the original. Those little hairs on the claws are what gives it away. I know exactly what you mean about the legs not looking natural. That's why I cut them off of the baits I was making. They just didn't look right. I was thinking of doing something similar to what you did, but for now I'm going to leave them as is.

The antennae idea is a good one. I made a couple of open pour craw worm molds using a Venom hollow body craws, (pretty much the same as the Mad Man craw worms but with a hollow body. Since it was an open pour I couldn't leave the antennae on when making the mold so I was going to use living rubber strands for the antennae, because I could get it in thicker widths. But the colors are limited. I may do the same as you did with the silicone strands though as I am not real happy with the antennae on my baits.

Thanks for sharing the photo of your baits. They look sweet, and even though it's a dark color, I can still see the detail really well.

This mold making stuff is a lot of fun !!! lol

[Bassbme]

Just wanted to drop a post about the craw tube I made. I fished my first tournament with that bait on 6/6. It was a smaller tournament, 34 boats total, with a 5 fish limit. It was an open so you could either fish as a team, or fish my yourself. I fished it by myself and while I'm not sure, I probably ended up somewhere in the upper half of the field. I had a 5 fish limit of 10.15 lbs. Every fish came on one of the craw tubes I made. I tried a few other soft plastic baits, (Jackal Cover Craw, and a grub/ringworm bait I made) but when you get a fish on your third pitch with one of your baits, you kind of stick with it. lol I fished my craw tubes probably 75% of the time I was fishing a soft plastic bait.

The tourney payed 6 places, 13.04 took first. 11.99 took 6th. Of course we all lose fish, but I lost 2 that would have probably gotten me a check, and if the one was a bass, probably would have won it for me. The one I am sure was a bass was about a 2 1/2# fish, which would have been about a 1 pound up grade. The other fish I never saw. Whatever it was it was a good one. Pitched in by a bush and the line starts swimming off. I set the hook and the fish pulled about 6' of line off against the drag, which I had as tight as I could get it without using pliers. lol. Anyhow.... had it on for another 3 or 4 seconds and it pulled off. I'd like to think it was a bass, but I've caught some big flathead catfish when flipping and pitching at this lake, so it may have been a catfish. If the water temp wasn't in the mid 70's I would have thought it might be a big pike, but with how shallow the fish was and water temps, it was either a bass, or a catfish.

Oh well. sorry for in indulgence, but it's pretty awesome catching a fish on a bait you made.

[Les Young]

I lost one Friday night that cost us getting in the money, but every fish came on my plastics that i make.  Been that way for several years now & you're right there's nothing better than that.

Edited June 8, 2020 by Les Young